The present invention relates to an apparatus for mounting and dismounting tires, especially large tires, and of the type which has a rotatable wheel holder on which the wheel felly may be clamped, and various associated tools and holder means for such tools, preferably a pressure disc for pressing free the tire edges and a universal tool for forcing the tire edge over the felly edge by mounting and dismounting.
The known apparatuses of this kind are of two principal types, where the axis of rotation of the wheel holder is vertical or horizontal, respectively, i.e. with a felly holder disc positioned either as a horizontal table or placed upright. Both types have advantages and disadvantages, the lying wheels being easy to work with, but difficult to mount and remove, while the vertical wheels are easy to mount and to remove, but difficult to work with, especially when wheels of the so-called locking ring type are concerned.
The present invention provides for an apparatus of the said type, where the wheel holder is placed on a carrier portion, which relative to an apparatus frame is pivotal in such a manner that the wheel holder axis is rotatable through the horizontal plane between an obliquely or straightly upwardly projecting position and an obliquely or straightly downwardly projecting position, the associated tools being provided so as to be operative relative to wheels fastened to the wheel holder in both the upwardly and the downwardly projecting position of its axis.
Hereby it is provided that the wheel holder axis may be brought to assume a position, i.e. a horizontal or a slightly upwardly inclined position, in which the wheel is mainly "lying", preferably entirely horizontal, so that it is easy to work with. In those cases where the tire is to be removed entirely for reparation or change, this apparatus will make it possible to loosen the tire from the felly with the wheel holder turning downwards, such that aided by gravity the tire may be loosened by a substantially reduced pressure force and simply fall from the felly without any strenuous manual assistance as required hitherto. This will be a very substantial advantage for the handling of heavy tires, e.g. for trucks, tractors, and constructors' machines. When mounting the old tire or a new one, the tire may be conveyed to the felly while this assumes a vertical position or a slightly vertically inclined position by which it is easy to bring the tire into initial connection with the felly, such that thereafter the felly and the tire may be pivoted to a more advantageous, horizontal mounting position without the heavy tire needing to be handled manually.
When delivering the wheel from the apparatus, the wheel may be turned to a vertical position, optionally slightly outwardly inclined from the wheel holder, such that it may easily be released from its holding engagement with the wheel holder, and thereafter be rolled away.
It will be a further possibility that the wheel or especially a tire dismounted therefrom can be released from the apparatus in a "lying" position, in being released from the wheel holder with this being turned downwards such that the wheel or the tire in a horizontal position can fall down onto a horizontal base, which may be provided with horizontal conveyor rollers, by means of which the lying wheel or tire may easily be drawn away from the apparatus.
It is known in the art that for pressing the tire edges free on both felly sides, two pressure discs may be used, one for each side of the mounted wheel. The invention provides for a correspondingly advantageous possibility by means of a single pressure disc, this being caused to cooperate with first one side of the tire, then the other side, by turning the wheel holder.
Preferably the wheel holder is placed on a carrier member which also carries the motor by means of which the wheel holder may be pivoted, which carrier portion as a whole being pivotable for turning the wheel holder between the upwardly and the downwardly projecting position. The carrier member is advantageously mounted so as to be rotatable or displaceable also for allowing the wheel holder to be moved in a vertical direction, such that with its holding shaft oriented "lying" it may receive and deliver an upstanding wheel, respectively pivot the wheel through its vertical position and yet bring the now lying wheel down to a comfortable working height, which is of course especially relevant for very large wheels.
The same height mobility of the wheel holder carrier member may then also be utilized for producing the clamping movement in the orientation of the wheel which is necessary for enabling the pressure disc to perform its operation.